1.利用 lim _(narrow infty )((1+dfrac {1)(n))}^n=e 求下列极限:-|||-(1) lim _(narrow infty )((1-dfrac {1)(n))}^n;-|||-(2) lim _(narrow infty )((1+dfrac {1)(n))}^n+1;-|||-(3) lim _(narrow infty )((1+dfrac {1)(n+1))}^n;